In a medium size pan, heat oil on medium heat. Add the vadi and cook till they are golden brown, about 2~3 minutes. Remove them onto a plate and set aside.
To the same pan, add bay leaf, cinnamon stick and cumin seeds. Once the seeds start to splutter, add the ginger, green chilies and tomatoes. Cook covered for 2~3 minutes or until tomatoes are mushy.
Add chopped bottle gourd, turmeric, ground cumin, red chili powder and salt. Sauté uncovered for 2~3 minutes. Then cover and cook, stirring occasionally, until the bottle gourd is tender, about 10~12 minutes.
Turn off the heat and crumble the fried vadi on top and serve with steamed rice.